Methods and systems for energy management of a transport climate control system

ABSTRACT

A method for managing energy to a transport climate control system from a vehicle electrical system is provided. The vehicle electrical system includes a vehicle power network and an auxiliary power network connected to a transport climate control load network via a DC regulated bus. The method includes monitoring a vehicle voltage of the vehicle power network and determining whether the vehicle power network requires holdover assistance based on the vehicle voltage. Also, the method includes the bus sending vehicle power energy generated by the vehicle power network to the transport climate control load network without assistance of the auxiliary power network when the controller determines that the vehicle power network has sufficient power capacity available, and the bus sending the vehicle power energy and auxiliary power energy stored by the auxiliary power network to the transport climate control load network when the controller determines that the vehicle power network requires holdover assistance.

FIELD

This disclosure relates generally to energy management of a transport climate control system. More specifically, the disclosure relates to methods and systems for managing multiple energy sources for a transport climate control system.

BACKGROUND

A transport climate control system can include, for example, a transport refrigeration system (TRS) and/or a heating, ventilation and air conditioning (HVAC) system. A TRS is generally used to control an environmental condition (e.g., temperature, humidity, air quality, and the like) within a cargo space of a transport unit (e.g., a truck, a container (such as a container on a flat car, an intermodal container, etc.), a box car, a semi-tractor, a bus, or other similar transport unit). The TRS can maintain environmental condition(s) of the cargo space to maintain cargo (e.g., produce, frozen foods, pharmaceuticals, etc.) In some embodiments, the transport unit can include a HVAC system to control a climate within a passenger space of the vehicle.

SUMMARY

This disclosure relates generally to energy management of a transport climate control system. More specifically, the disclosure relates to methods and systems for managing multiple energy sources for a transport climate control system.

The embodiments described herein can maintain climate control of an internal space of a transport unit (e.g., cargo space, passenger space, etc.) when available energy capacity from one or more energy sources is inconsistent.

This disclosure discloses a vehicle electrical system for managing loads and multiple energy sources to allow for management of electrical energy to provide power to a transport climate control system (also referred to as a HVAC-R system) even if the vehicle power source (for example, the prime mover) is off or unable to fully power the climate control system (“holdover”). In addition, the vehicle electrical system can provide a boost to the vehicle power using an auxiliary energy source (e.g., auxiliary battery) when the vehicle power (for example, from the prime mover) is insufficient.

It will be appreciated that there can be multiple reasons for why the vehicle power source is limited. For example, the vehicle alternator might not be rated for the capacity needed for the loads. Another example is that the vehicle is slowing down (i.e., the vehicle is not running a full speed), and thus the vehicle alternator is not provided by the vehicle a full capacity (for example, the vehicle alternator is provided with 70% or 65% of the rated capacity). For example, the vehicle alternator at 100 A can only provide 70 A or 65 A as the vehicle is slowing down. For the vehicle equipped with auto start-stop system (for example, to comply with the EU emission standard), the vehicle can shut down completely when the vehicle comes to a standstill stop (i.e., the vehicle alternator provides no current).

Regulations to reduce emissions (e.g., particulate matter emissions, nitrogen oxide emissions, noise emissions, etc.), for example, from a vehicle prime mover (e.g., a combustion engine such as a diesel engine, etc.), have led to components within the vehicle being electrically driven and the addition of emission reducing components (e.g., emission control devices, an auto start-stop system, etc.) in the space between the vehicle alternator and the prime mover within a vehicle power bay. The auto start-stop system can shut the prime mover off (i.e., the prime mover is not running) when, for example, the vehicle stops at a traffic light, stops at a store, etc. Accordingly, the amount of space between the vehicle alternator and the prime mover in the vehicle power bay that is available for other components is shrinking. For example, this reduced space can make it difficult to provide a separate compressor coupled to (or tied to, mounted to) the prime mover in the vehicle power bay to provide for high cooling power load and supplement a transport climate control system.

The embodiments described herein can provide a transport climate control system that can be electrically driven by the power (for example, a 12V DC power) from the vehicle alternator. Also, the embodiments described herein can help to ensure that power for supply loads (e.g., the transport climate control system) is available as required. In particular, the embodiments described herein can ensure that the transport climate control system always has required power, by means of controlled hardware and power management algorithms to optimize vehicle power input, and by utilizing an attached auxiliary energy storage when necessary. The embodiments described herein can effectively manage multiple power sources and manage and optimize different input and output of the power.

Also, the embodiments described herein can provide climate control within an internal space using a compressor that is disposed outside of the vehicle power bay and is driven by an electric drive. This can prevent the need for a compressor in the vehicle power bay and thereby increase the amount of space available in the vehicle power bay and can allow the separate compressor to operate even when the vehicle prime mover off.

In one embodiment, a method for managing energy to a transport climate control system from a vehicle electrical system is provided. The vehicle electrical system includes a vehicle power network and an auxiliary power network connected to a transport climate control load network via a DC regulated bus. The method includes monitoring a vehicle voltage of the vehicle power network. The method also includes a controller determining whether the vehicle power network has sufficient power capacity available and whether the vehicle power network requires holdover assistance based on the vehicle voltage. Also, the method includes the DC regulated bus sending vehicle power energy generated by the vehicle power network to the transport climate control load network without assistance of the auxiliary power network when the controller determines that the vehicle power network has sufficient power capacity available. Further, the method includes the DC regulated bus sending the vehicle power energy generated by the vehicle power network and auxiliary power energy stored by the auxiliary power network to the transport climate control load network when the controller determines that the vehicle power network requires holdover assistance.

In another embodiment, a vehicle electrical system for managing energy to a transport climate control system is provided. The vehicle electrical system includes a direct current (DC) regulated bus, a vehicle power network, an auxiliary power network, a transport climate control load network, and a controller. The vehicle power network is configured to generate power from a vehicle and provide the generated power to the DC regulated bus. The auxiliary power network includes an auxiliary battery system connected to the DC regulated bus. The auxiliary battery system is configured to store power and supply the stored power to the DC regulated bus. The transport climate control load network receives power from the DC regulated bus. The controller is configured to monitor a vehicle voltage of the vehicle power network, and determine whether the vehicle power network has sufficient power capacity available and whether the vehicle power network requires holdover assistance based on the vehicle voltage. The DC regulated bus is configured to send vehicle power energy generated by the vehicle power network to the transport climate control load network without assistance of the auxiliary power network when the controller determines that the vehicle power network has sufficient power capacity available. The DC regulated bus is configured to send vehicle power energy generated by the vehicle power network and auxiliary power energy stored by the auxiliary power network to the transport climate control load network when the controller determines that the vehicle power network requires holdover assistance

BRIEF DESCRIPTION OF THE DRAWINGS

References are made to the accompanying drawings that form a part of this disclosure and which illustrate embodiments in which the systems and methods described in this specification can be practiced.

FIG. 1A illustrates a side view of a truck with a front wall mounted vehicle powered transport refrigeration unit, according to one embodiment.

FIG. 1B illustrates a schematic cross sectional side view of a refrigerated transport unit with a multi-temp transport refrigeration system, according to one embodiment.

FIG. 1C illustrates a perspective view of a vehicle with an APU, according to one embodiment.

FIG. 1D illustrates a front perspective view of an APU, according to one embodiment.

FIG. 1E illustrates a side view of a van with a roof mounted vehicle powered transport refrigeration unit, according to one embodiment.

FIG. 2 illustrates a block diagram schematic of one embodiment of a vehicle electrical system of a climate control system, according to one embodiment.

FIG. 3 illustrates a block diagram schematic of one embodiment of an Energy Management Module, according to one embodiment.

FIG. 4 illustrates a flowchart of one embodiment of a method for managing energy to a transport climate control load network from a vehicle electrical system.

Like reference numbers represent like parts throughout.

DETAILED DESCRIPTION

This disclosure relates generally to energy sources and loads management. More specifically, the disclosure relates to methods and systems for managing and controlling auxiliary electrical storage and loads for multiple energy sources for a climate control system.

The embodiments described herein can be provided in, for example, a transport climate control system such as a TRS or MTRS for a transport unit (TU), an HVAC system for a vehicle, etc.

As defined herein, “low voltage” refers Class A of the ISO 6469-3 in the automotive environment. In particular, a maximum working voltage of between 0V and 60V DC or between 0V and 30V AC.

As defined herein, “high voltage” refers Class B of the ISO 6469-3 in the automotive environment. In particular, a maximum working voltage of between 60V and 1500V DC or between 30V and 1000V AC.

FIG. 1A depicts a temperature-controlled straight truck 11 that includes a conditioned load space 12 for carrying cargo. A transport refrigeration unit (TRU) 14 is mounted to a front wall 16 of the load space 12. The TRU 14 is controlled via a controller 15 to provide temperature control within the load space 12. The truck 11 further includes a vehicle power bay 18, which houses a prime mover 21, such as a combustion engine (e.g., diesel engine, etc.), that provides power to move the truck 11 and to operate the TRU 14. In some embodiments, the prime mover 21 can work in combination with an optional machine 22 (e.g., an alternator) to operate the TRU 14. In one embodiment, the TRU 14 includes a vehicle electrical system (see FIG. 2). Also, in some embodiments, the truck 11 can be a hybrid vehicle that is powered by the prime mover 21 in combination with a battery power source or can be an electrically driven truck in which the prime mover 21 is replaced with an electric power source (e.g., a battery power source).

While FIG. 1A illustrates a temperature-controlled straight truck 11, it will be appreciated that the embodiments described herein can also apply to any other type of transport unit including, but not limited to, a container (such as a container on a flat car, an intermodal container, etc.), a box car, or other similar transport unit.

FIG. 1B illustrates one embodiment of a MTRS 100 for a TU 125 that can be towed, for example, by a tractor (not shown). The MTRS 100 includes a TRU 110 that provides environmental control (e.g. temperature, humidity, air quality, etc.) within an internal space 150 of the TU 125. The MTRS 100 also includes a MTRS controller 170 and one or more sensors (e.g., Hall effect sensors, current transducers, etc.) (see FIG. 2) that are configured to measure one or more parameters (e.g., ambient temperature, compressor suction pressure, compressor discharge pressure, supply air temperature, return air temperature, humidity, etc.) of the MTRS 100 and communicate parameter data to the MTRS controller 170. The MTRS 100 is powered by a power module 112. The TRU 110 is disposed on a front wall 130 of the TU 125. In other embodiments, it will be appreciated that the TRU 110 can be disposed, for example, on a rooftop 126 or another wall of the TU 125.

In some embodiments, the MTRS 100 can include an undermount unit 113. In some embodiments, the undermount unit 113 can be a TRU that can also provide environmental control (e.g. temperature, humidity, air quality, etc.) within the internal space 150 of the TU 125. The undermount unit 113 can work in combination with the TRU 110 to provide redundancy or can replace the TRU 110. Also, in some embodiments, the undermount unit 113 can be a power module that includes, for example, a generator that can help power the TRU 110.

The programmable MTRS Controller 170 may comprise a single integrated control unit or may comprise a distributed network of TRS control elements. The number of distributed control elements in a given network can depend upon the particular application of the principles described herein. The MTRS controller 170 is configured to control operation of the MTRS 100.

As shown in FIG. 1B, the power module 112 is disposed in the TRU 110. In other embodiments, the power module 112 can be separate from the TRU 110. Also, in some embodiments, the power module 112 can include two or more different power sources disposed within or outside of the TRU 110. In some embodiments, the power module 112 can include one or more of a prime mover, a battery, an alternator, a generator, a solar panel, a fuel cell, etc. Also, the prime mover can be a combustion engine or a microturbine engine and can operate as a two speed prime mover, a variable speed prime mover, etc. The power module 112 can provide power to, for example, the MTRS Controller 170, a compressor (not shown), a plurality of DC (Direct Current) components (not shown), a power management unit (see FIG. 2), etc. The DC components can be accessories or components of the MTRS 100 that require DC power to operate. Examples of the DC components can include, for example, DC fan motor(s) for a condenser fan or an evaporator blower (e.g., an Electrically Commutated Motor (ECM), a Brushless DC Motor (BLDC), etc.), a fuel pump, a drain tube heater, solenoid valves (e.g., controller pulsed control valves), etc.

The power module 112 can include a DC power source (not shown) for providing DC electrical power to the plurality of DC components (not shown), the power management unit (see FIG. 2), etc. The DC power source can receive mechanical and/or electrical power from, for example, a utility power source (e.g., Utility power, etc.), a prime mover (e.g., a combustion engine such as a diesel engine, etc.) coupled with a generator machine (e.g., a belt-driven alternator, a direct drive generator, etc.), etc. For example, in some embodiments, mechanical energy generated by a diesel engine is converted into electrical energy via a generator machine. The electrical energy generated via the belt driven alternator is then converted into DC electrical power via, for example, a bi-directional voltage converter. The bi-directional voltage converter can be a bi-directional multi-battery voltage converter.

The internal space 150 can be divided into a plurality of zones 152. The term “zone” means a part of an area of the internal space 150 separated by walls 175. It will be appreciated that the invention disclosed herein can also be used in a single zone TRS.

The MTRS 100 for the TU 125 includes the TRU 110 and a plurality of remote evaporator units 180. In some embodiments, an HVAC system can be powered by an Auxiliary Power Unit (APU, see FIGS. 1C and 1D). The APU can be operated when a main prime mover of the TU 125 is turned off such as, for example, when a driver parks the TU 125 for an extended period of time to rest. The APU can provide, for example, power to operate a secondary HVAC system to provide conditioned air to a cabin of the TU 125. The APU can also provide power to operate cabin accessories within the cabin such as a television, a microwave, a coffee maker, a refrigerator, etc. The APU can be a mechanically driven APU (e.g., prime mover driven) or an electrically driven APU (e.g., battery driven).

The tractor includes a vehicle electrical system (see FIG. 2) for supplying electrical power to the electrical loads of the tractor, the MTRS 100, and/or the TU 125.

FIG. 1C illustrates a vehicle 10 according to one embodiment. The vehicle 10 is a semi-tractor that is used to transport cargo stored in a cargo compartment (e.g., a container, a trailer, etc.) to one or more destinations. Hereinafter, the term “vehicle” shall be used to represent all such tractors and trucks, and shall not be construed to limit the invention's application solely to a tractor in a tractor-trailer combination. In some embodiments, the vehicle 10 can be, for example, a straight truck, van, etc.

The vehicle 10 includes a primary power source 20, a cabin 25 defining a sleeping portion 30 and a driving portion 35, an APU 40, and a plurality of vehicle accessory components 45 (e.g., electronic communication devices, cabin lights, a primary and/or secondary HVAC system, primary and/or secondary HVAC fan(s), sunshade(s) for a window/windshield of the vehicle 10, cabin accessories, etc.). The cabin 25 can be accessible via a driver side door (not shown) and a passenger side door 32. The cabin 25 can include a primary HVAC system (not shown) that can be configured to provide conditioned air within driving portion 35 and potentially the entire cabin 25, and a secondary HVAC system (not shown) for providing conditioned air within the sleeping portion 30 of the cabin 25. The cabin 25 can also include a plurality of cabin accessories (not shown). Examples of cabin accessories can include, for example, a refrigerator, a television, a video game console, a microwave, device charging station(s), a continuous positive airway pressure (CPAP) machine, a coffee maker, a secondary HVAC system for providing conditioned air to the sleeping portion 30.

The primary power source 20 can provide sufficient power to operate (e.g., drive) the vehicle 10 and any of the plurality of vehicle accessory components 45 and cabin accessory components 47. The primary power source 20 can also provide power to the primary HVAC system and the secondary HVAC system. In some embodiments, the primary power source can be a prime mover such as, for example, a combustion engine (e.g., a diesel engine, etc.).

The APU 40 is a secondary power unit for the vehicle 10 when the primary power source 20 is unavailable. When, for example, the primary power source 20 is unavailable, the APU 40 can be configured to provide power to one or more of the vehicle accessory components, the cabin accessories, the primary HVAC system and the secondary HVAC system. In some embodiments, the APU 40 can be an electric powered APU. In other embodiments, the APU 40 can be a prime mover powered APU. The APU 40 can be attached to the vehicle 10 using any attachment method. In some embodiments, the APU 40 can be turned on (i.e., activated) or off (i.e., deactivated) by an occupant (e.g., driver or passenger) of the vehicle 10. The APU 40 generally does not provide sufficient power for operating (e.g., driving) the vehicle 10. The APU 40 can be controlled by an APU controller 41.

FIG. 1D illustrates an electric APU 140 that can be used with a vehicle (e.g., the vehicle 10 shown in FIG. 1C), according to one embodiment. The APU 140 includes a plurality of energy storage elements 60 each of which is coupled to one of a plurality of converters 70. The converters 70 can provide electric power (e.g., AC or DC power) generated by the APU 140 to one or more vehicle accessory components, cabin accessory components, a primary HVAC system, and a secondary HVAC system. A secondary HVAC system can provide conditioned air to a sleeping portion of a vehicle cabin (e.g., the sleeping portion 30 of the cabin 25 shown in FIG. 1C). The energy storage elements 60 can be, for example, battery packs, fuel cells, etc. In some embodiments, the APU 140 can be turned on or off by an occupant (e.g., driver or passenger) of the vehicle. For example, the occupant can turn on the APU 140 to provide power stored in the energy storage elements 60 when a primary power source of the vehicle is turned off. It will be appreciated that the embodiments described herein can also be used with a prime mover powered APU.

In some embodiments, the APU (e.g., the APU 40 as shown in FIG. 1C and/or the APU 140 as shown in FIG. 1D) includes a vehicle electrical system (see FIG. 2).

FIG. 1E depicts a temperature-controlled van 80 that includes a conditioned load space 82 (or internal space) for carrying cargo. A transport refrigeration unit (TRU) 85 is mounted to a rooftop 84 of the load space 82. The TRU 85 is controlled via a controller 83 to provide temperature control within the load space 82. The van 80 further includes a vehicle power bay 86, which houses a prime mover 87, such as a combustion engine (e.g., diesel engine, etc.), that provides power to move the van 80 and to operate the TRU 85. In some embodiments, the prime mover 87 can work in combination with an optional machine 88 (e.g., an alternator) to operate the TRU 85. In one embodiment, the TRU 85 includes a vehicle electrical system (see FIG. 2). Also, in some embodiments, the van 80 can be a hybrid vehicle that is powered by the prime mover 87 in combination with a battery power source or can be an electrically driven truck in which the prime mover 87 is replaced with an electric power source (e.g., a battery power source).

FIG. 2 illustrates a block diagram schematic of one embodiment of a vehicle electrical system 200. The vehicle electrical system 200 can be provided, for example, in the TRU 14 shown in FIG. 1A to supply electrical power to the TRU 14. Also, the vehicle electrical system 200 can be provided to supply electrical power to the electrical loads of the tractor, the MTRS 100, and/or the TU 125 shown in FIG. 1B. The vehicle electrical system 200 can also be provided as part of an APU (e.g., the APU 40 shown in FIG. 1C and/or the APU 140 shown in FIG. 1D) to supply electrical power to one or more loads connected to the APU. The vehicle electrical system 200 shown in FIG. 2 is configured to operate with a prime mover powered vehicle. However, it will be appreciated that the vehicle electrical system 200 can also be configured to operate with an electric vehicle powered by an energy storage device (e.g., one or more batteries) and/or a hybrid vehicle powered by a combination of a prime mover and an energy storage device.

As shown in FIG. 2, the vehicle electrical system 200 includes a DC regulated bus 202 electrically connecting a vehicle power network 204, an auxiliary power network 206, a utility power network 208, a bi-directional voltage converter 240 and a transport climate control load network 212. In some embodiments, the DC regulated bus 202 can be a 12 volts DC regulated bus. It will be appreciated that “regulated” is a term of art. For example, a regulated power supply can convert unregulated AC (Alternating Current) supply into a constant DC, with the help of a rectifier (or an AC-DC converter, or the like), and can supply a stable voltage (or current in some situations), to a circuit or device that need to be operated within certain power supply limits. It will also be appreciated that on a 12 volt regulated bus, the voltage provided to the bus can vary, for example, between about 11 volts to about 15 volts. In some embodiments, the DC regulated bus 202 can travel from a vehicle power bay to a cab of the vehicle, to a TRU, and/or to a APU.

The vehicle electrical system 200 can manage and regulate energy from one or more energy sources from the vehicle power network 204, the auxiliary power network 206 and/or the utility power network 208 to the transport climate control load network 212 via the bi-directional voltage converter 240. The one or more energy sources can include a vehicle battery 210 and an vehicle alternator 205 via the vehicle power network 204, a utility power 220 (also referred to as a shore power source) via the utility power network 208, and/or one or more auxiliary batteries 230 via the auxiliary power network 206. Also, the vehicle electrical system 200 is configured to supply energy to one or more loads from the transport climate control load network 212. The loads can be, for example, a compressor 255, one or more evaporator blowers 265, one or more condenser fans 270, a heater 275, and a controller 260 of an transport climate control system.

The vehicle power network 204 includes the vehicle battery 210, the vehicle alternator 205 and a vehicle isolator 215 disposed between the vehicle alternator 205 and the vehicle battery 210 at one end and the DC regulated bus 202 at a second end. The vehicle battery 210 can be used, for example, for starting a vehicle prime mover, running lights, powering vehicle accessory components, etc. In some embodiments, the vehicle battery 210 can also be used to power components of the transport climate control load network 208. The vehicle battery 210 and the vehicle alternator 205 are connected to the DC regulated bus 202 via a vehicle isolator 215. In one embodiment, the vehicle isolator 215 can be a switch controlled by the controller 260 that isolates the bi-directional voltage converter 240 from receiving energy from the vehicle power network 204.

The vehicle alternator 205 can be an electrical alternator that can provide AC power to the vehicle. In some embodiments, the vehicle alternator 205 can include a rectifier or an AC-DC converter (not shown) that rectifies or converts the AC power to a DC power. The vehicle alternator 205 is connected to the DC regulated bus 202 via the vehicle isolator 215. The vehicle alternator 205 can provide the rectified or converted DC power (for example, 12V) to the DC regulated bus 202.

It will be appreciated that in electric vehicles, there may be no alternator. Electric vehicles can include a motor generator and a high voltage (e.g., in a range between 60V and 1500V; for example 400V, 800V, etc.) DC battery to run the vehicle. Electric vehicles can also provide a relatively high voltage (e.g., 400V, 800V, etc.) DC power source (e.g., a battery pack, a rechargeable energy storage system (RESS), etc.). Electric vehicles can include one or more DC-DC converters (e.g., two DC-DC convertors) to convert the relatively high voltage (e.g., 400V, 800V, etc.) to a low voltage (e.g., in a range between 0V and 60V; for example 12V). That is, the vehicle alternator 205 can be replaced with a DC-DC converter having similar parameters as the vehicle alternator 205 in order to be able to provide a low voltage to the DC regulated bus 202 and power one or more loads of the transport climate control load network 212. The converted low voltage (e.g. 12V) can be used to power vehicle accessory components (e.g., electronic communication devices, cabin lights, a primary and/or secondary HVAC system, primary and/or secondary HVAC fan(s), sunshade(s) for a window/windshield of the vehicle 10, cabin accessories, etc.). In some embodiments, the converted low voltage (e.g. 12V) can be provided to the DC regulated bus 202 for powering the transport climate control load network 212. In some embodiments, an electric vehicle can provide for example, 7 kW-Hour energy from a 45 kW-Hour storage of the vehicle power network 204 to run the transport climate control load network 212. It will be appreciated that the embodiments disclosed herein is directed to a low voltage (e.g., 12V) system. Embodiments disclosed herein can use take off power (e.g., electric power take off or ePTO) from the low voltage (for example, 12V) system for loads such as vehicle accessory components and/or the transport climate control load network 212. The high voltage power can provide power for driving the vehicle (e.g., transmission power take off) and the embodiments disclosed herein may not take electric power from the high voltage system.

It will be appreciated that in a hybrid vehicle, there may be an alternator (such as the vehicle alternator 205) and/or a low voltage DC power source that can provide a low voltage (e.g., 12V) to the DC regulated bus 202.

It will be appreciated that any type of power source from the vehicle that can provide power to the vehicle electrical system 200 can be part of the vehicle power network 204. This can include, for example, the vehicle alternator 205, the vehicle battery 210, a RESS, a generator, an axle-mounted generator, a power take off (PTO) device or ePTO device with an auxiliary converter, etc.

In some embodiments, a voltage sensor (not shown) can be provided in the vehicle power network 204 to monitor a vehicle voltage provided to the DC regulated bus 202. Also, in some embodiments, a current sensor (not shown) can be provided in series with the vehicle isolator 215 to monitor the current to and from the auxiliary power network 206.

The utility power network 208 includes the AC-DC converter 225. A utility power (e.g., Utility power, etc.) 220 can be connected to the AC-DC converter 225 to provide AC power input to the AC-DC converter 225. The AC-DC converter 225 converts the AC power from the utility power 220 and provides converted DC power to the DC regulated bus 202. In one embodiment, the converted DC power from the AC-DC converter 225 to the DC regulated bus 202 can be, for example, 12 volts and 84 amps. While FIG. 2 shows a single AC-DC converter 225, it is appreciated that in other embodiments the vehicle electrical system 200 can includes two or more AC-DC converters. In embodiments where there are two or more AC-DC converters, each of the AC-DC converters can be connected to the utility power 220 to provide additional power capacity to the vehicle electrical system 200. In some embodiments, each of the AC-DC converters can provide different amounts of power. In some embodiments, each of the AC-DC converters can provide the same amount of power.

The auxiliary power network 206 includes an optional auxiliary battery system 230 and two auxiliary power on/off switches 235 disposed between the auxiliary battery system 230 and the DC regulated bus 202. In some embodiments, the auxiliary power network 206 can be part of the transport climate control system and potentially housed within a transport refrigeration unit. In other embodiments, the auxiliary power network 206 can be external to the transport climate control system and part of the vehicle power network 204. In yet some other embodiments, the auxiliary power network 206 can be external to the transport climate control system and external to the vehicle power network 204.

In some embodiments, the auxiliary battery system 230 can include a one or more auxiliary batteries (also referred to as hold-over batteries). For example, in one embodiment the auxiliary battery system 230 can include two auxiliary batteries (not shown). Each of the auxiliary batteries can also be connected to the DC regulated bus 202 via the bi-directional voltage converter 240. Also, each of the auxiliary batteries can bypass the bi-directional voltage converter 240 and connect to the DC regulated bus 202 via one of the auxiliary power on/off switches 235. It will be appreciated that the auxiliary battery system 230 can provide sufficient energy to power the transport climate control load network 212 by itself. Each of the auxiliary power on/off switches 235 can be controlled by the controller 260.

The bi-directional voltage converter 240 is configured to transfer power from one of the vehicle power network 204, the utility power network 208 and/or the auxiliary power network 206 to the transport climate control load network 212. In some embodiments, the bi-directional voltage converter 240 can be part of an energy management module (e.g., a smart charge module (SCM), etc.). In these embodiments, the bi-directional voltage converter 240 can transfer power from the vehicle power network 204 and/or the utility power network 208 to charge one or more auxiliary batteries of the auxiliary battery system 230. Thus, the bi-directional voltage converter 240 can control current flow along the DC regulated bus 202. In some embodiments, the vehicle electrical system 200 can include two or more bi-directional voltage converters 240 each of which is part of a separate SMC. As described in more detail in FIG. 3, the energy management module can be a DC-DC charger. The bi-directional voltage converter 240 can step-down (buck) and step-up (boost) voltage for power being sent from the vehicle power network 204 and/or the utility power network 208 to the bi-directional voltage converter 240, and from the bi-directional voltage converter 240 to the vehicle power network 204 and/or the utility power network 208. Accordingly, the bi-directional voltage converter 240 can control current direction and current amount along the DC regulated bus 202.

The vehicle electrical system 200, and particularly the bi-directional voltage converter 240, is controlled by the controller 260. The controller 260 can be, for example, the TRS controller 15 shown in FIG. 1A, the MTRS controller 170 of FIG. 1B, or the APU controller 41. A remote controller 280 can be connected to the controller 260 wirelessly (e.g., Bluetooth, ZigBee, etc.) or via wire (e.g., a communication link such as a RS485 communication link). The remote controller 280 can be located in a cab of the vehicle and can be controlled by a user, for example, a driver. The remote controller 280 can be used by a user to communicate the user's settings for components of the transport climate control load network 212 to the controller 260.

Components of the transport climate control load network 212 can be, for example, part of a TRU that is mounted to the body of the vehicle (for example, truck). In some embodiments, the TRU can be above the cab of the truck. In another embodiment, the TRU can be on the top of the TU (for example, a top of a box where the external condensers are located). The transport climate control load network 212 includes a Compressor Drive Module (CDM) 250 that drives the compressor 255, one or more evaporator blowers 265, one or more condenser fans 270, the heater 275, and the controller 260. The DC regulated bus 202 is connected to and powers each of the CDM 250, the one or more evaporator blowers 265, the one or more condenser fans 270, the heater 275, and the controller 260. It will be appreciated that the CDM 250 and the compressor 255 can require the most power of the various loads of the transport climate control load network 212.

The CDM 250 is configured to boost power from the DC regulated bus 202 and converts the power to AC power to drive the compressor 255. In some embodiments, the CDM 250 can convert the low voltage DC power (for example, 12V) from the DC regulated bus 202 and provide, for example, 240V AC power to drive the compressor 255. In particular, the CDM 250 drives the compressor 255 to meet demand of the transport climate control system. When the vehicle alternator 205 alone cannot supply sufficient current to the transport climate control load network 212, the CDM 250 can cause the vehicle voltage to droop. In some embodiments, the CDM 250 includes a DC-DC-AC converter in which the CDM 250 boosts the voltage from the DC regulated bus to a higher DC voltage and then converts the higher DC voltage to an AC voltage.

In some embodiments, the utility power 220 can be connected directly to the compressor 255 and provide power to drive the compressor 255 thereby bypassing the CDM 250. In some embodiments, the CDM 250 can be used as an AC-DC converter and convert power received from the utility power 220 into DC power that can be provided by the CDM 250 to the DC regulated bus 202.

In some embodiments, the compressor 255 can be a variable speed compressor. In some embodiments, the compressor 255 can require, for example, 1 KW of power to operate. In some embodiments, the one or more evaporator blowers 265 can require, for example, 100 W of power to operate. In some embodiments, the one or more condenser fans 270 can require, for example, 130 W of power to operate. In some embodiments, the heater 275 can require, for example, 1200 W of power to operate. Also, in some embodiments, the heater 275 can be configured to receive power from the CDM 250.

When the compressor 255 and/or the heater 275 are powered directly by the utility power 220, the compressor 255 and/or the heater 275 can be turned on and off (e.g., operate in a cycle sentry mode) in order to control the amount of cooling provided by the compressor 255 and/or the amount of heating provided by the heater 275.

FIG. 3 illustrates a block diagram schematic of one embodiment of an energy management module 300. A vehicle power network 304 is electrically connected to the energy management module 300. The vehicle power network 304 can include one or more vehicle power sources such as, for example, a vehicle alternator (e.g., the vehicle alternator 205), a vehicle battery (e.g., the vehicle battery 210), etc. The energy management module 300 includes a bi-directional voltage converter 330. The bi-directional voltage converter 330 can be, for example, the bi-directional voltage converter 240 shown in FIG. 2. The bi-directional voltage converter 330 can step-down (buck) and step-up (boost) voltage for power being sent from the vehicle power network 304 to the energy management module 300 and from the energy management module 300 to the vehicle power network 304. Accordingly, the bi-directional voltage converter 240 can control current direction and current amount along a DC regulated bus of a vehicle electrical system. Detailed descriptions on some embodiments of the bi-directional voltage converters can be found in, for example, U.S. Pat. Nos. 8,441,228; 8,541,905; 9,199,543; and 9,102,241. The energy management module 300 includes a plurality of electric switches 310, 311, and 312. Each of the electric switches 310, 311, and 312 connects to (or disconnects from) a corresponding battery module 340, 341, and 342, respectively. The battery modules 340, 341, and 342 can be, for example, the auxiliary battery system 230 shown in FIG. 2.

In some embodiments, the plurality of electric switches 310, 311, and 312 can be battery relays, electronic switches, etc. In some embodiments, the electronic switches 310, 311, and 312 can be, for example, semiconductor (solid-state) switches such as SmartFET type switches. SmartFET type switches can be field-effect transistor (FET) switches that have smart built-in features such as diagnosis and protection capabilities. In some embodiments, one or more of the battery modules 340, 341, and 342 can be an auxiliary battery used to power components of the transport climate control load network 212. In some embodiments, the plurality of electric switches 310, 311, and 312 is configured to selectively connect one or more of the battery modules 340, 341, and 342 to the bi-directional voltage converter 330 so that at any given time, a subset of the battery modules 340, 341, and 342 connects to the bi-directional voltage converter 330. A controller (such as, for example, the controller 260 shown in FIG. 2) can be configured to control the plurality of electric switches 310, 311, 312 to selectively connect one or more of the battery modules 340, 341, and 342 to the bi-directional voltage converter 330.

It will be appreciated that in certain embodiments, the plurality of electric switches 310, 311, and 312 can be configured to selectively connect more than one of the battery modules 340, 341, and 342 to the bi-directional voltage converter 330. It will also be appreciated that the plurality of electric switches 310, 311, and 312 can be a single battery relay or a single electronic switch that can be configured to selectively connect one or more of the plurality of battery modules 340, 341, and 342 to the bi-directional voltage converter 330.

The bi-directional voltage converter 330 can connect to a system bus of a vehicle electrical system (such as, for example, the DC regulated bus 202 shown in FIG. 2) so that the selected battery module(s) 340, 341, and 342 can deliver power to electrical loads (such as, for example, components of the transport climate control load network 212 shown in FIG. 2) of the vehicle electrical system or can be charged by other power sources. A controller (for example, the controller 260 shown in FIG. 2) can control/switch a plurality of switches (not shown) of the bi-directional voltage converter 330 to control when and where the bi-directional voltage converter 330 directs current (for example, from the selected battery module 340, 341, 342 to the electrical loads in a discharging mode, or from other power source to the selected battery module 340, 341, 342 in a charging mode).

It will be appreciated that the plurality of battery modules 340, 341, 342 of the energy management module 300 can charge (i.e., deliver power to) battery module(s) of another energy management module, or vice versa, to balance the power/energy stored in the battery module(s) of each energy management module. It will further be appreciated that battery module(s) of different energy management modules can be combined/selected until the total power-delivery capacity (e.g. measured in peak amperes at a given voltage, such as 12 volts) is sufficient for supplying the power needs of the vehicle electrical system. The selected battery module(s) of different energy management modules can provide adequate power to the electrical loads of the vehicle electrical system based on the load draw.

Generally, the selected battery module(s) of different energy management modules receive power from one or more power sources during a charge phase, and discharges power to the electrical loads of the vehicle electrical system during a discharge phase. A charge phase may occur when for example, a power source (such as, for example, the utility power network 208 shown in FIG. 2) provides power to the vehicle electrical system of the vehicle, and a discharge phase may occur when for example, the power source is not providing power to the vehicle electrical system of the vehicle (for example, when the prime mover (e.g., combustion engine) is stopped and utility power is unavailable). For example, utility power 208 can be used to fill an energy shortfall when the vehicle cannot be run and a temperature control gap between the monitored temperature and a desired setpoint temperature of the internal space conditioned by the transport climate control system is large. In some embodiments, a controller (e.g., the controller 260 shown in FIG. 2) can send an alert to a driver of the vehicle to request that the vehicle electrical system 200 be connected to the utility power 208 to address the energy shortfall. In some embodiments, the alert can instruct the driver to start the vehicle and run at a fast idle (e.g., raise an idle speed of a prime mover of the vehicle without raising a speed at which the vehicle is moving) or downshift a vehicle prime mover to operate at a higher prime mover RPM so as to prevent a failure of the transport climate control system and to prevent shedding or derating of loads of the transport climate control load network 212. In some embodiments, the controller 260 can instruct the vehicle to start an automatic restart module to start the vehicle and run at a fast idle to prevent failure of the transport climate control system and to prevent shedding or derating of loads of the transport climate control load network 212. In some embodiments, the controller 260 can instruct the vehicle to disable an auto start/stop system of the vehicle prime mover. In some embodiments, the alert can be sent a time period (e.g., 1 to 5 minutes) before any action is taken or required.

The bi-directional voltage converter 330 of the energy management module 300 can transfer power/energy between a power source and the selected battery module(s) 340, 341, and 342. The bi-directional voltage converter 330 is also referred to as a bi-directional multi-battery voltage converter. The bi-directional voltage converter 330 can include a control circuit (not shown). The control circuit can selectively energize one or more of the plurality of electric switches 310, 311, and 312 to connect the selected battery module(s) 340, 341, and 342 with the bi-directional voltage converter 330.

The energy management module 300 can operate in one of three modes: a charge mode, a discharge mode, and a null mode. When in a charge mode, the energy management module 300 can charge one or more of the battery modules 340, 341, and 342 using a power source (for example, the utility power 220 or the vehicle alternator 205 shown in FIG. 2). When in a discharge mode, the energy management module 300 can deliver power from one or more of the battery modules 340, 341, and 342 to the electrical loads (for example, components of the transport climate control load network 212 shown in FIG. 2). In the null mode, the energy management module 300 is configured to prevent current from flowing between any of the battery module 340, 341, and 342 and the rest of the vehicle electrical system. In the null mode, the control circuit is controlled such that none of the battery modules 340, 341, and 342 are energized.

The energy management module 300 operational modes can be determined by the controller (for example, the controller 260 shown in FIG. 2). The controller (for example, the controller 260 shown in FIG. 2) can switch the bi-directional voltage converter 330 ON (enabled) to draw current from a system bus of a vehicle electrical system or OFF (disabled) to prevent the bi-directional voltage converter 330 from drawing current. For example, when the bi-directional voltage converter 330 is switched ON in the charging mode, the bi-directional voltage converter 330 can direct current from one or more power sources to a selected battery module of the plurality of battery modules 340, 341, 342. When the bi-directional voltage converter 330 is switched ON in the discharging mode, the bi-directional voltage converter 330 can direct current from a selected battery module of the plurality of battery modules 340, 341, 342 to one or more electrical loads (e.g., components of the transport climate control load network 212 shown in FIG. 2). When the bi-directional voltage converter 330 is switched OFF, current can be prevented from flowing between the battery modules and the system bus via the bi-directional voltage converter 330.

FIG. 4 illustrates a flowchart of one embodiment of a method 400 for managing energy to the transport climate control load network 212 from the vehicle electrical system 200. The method 400 begins at 405 whereby the controller 260 determines whether the utility power network 208 is connected to the utility power 220 and the utility power network 208 is permitted to receive power from the utility power 220. In some embodiments, the utility power network 208 may be connected to the utility power 220 but not permitted to receive power from the utility power 220 when, for example, cost of power from the utility power 220 is too expensive, the use of utility power 220 by the vehicle electrical system 200 is being restricted, etc. In some embodiments, the controller 260 can be configured to monitor an ignition of the vehicle, determine that the utility power network 208 is permitted to receive power from the utility power 220 when the utility power 220 is connected to the utility power network 208 and the ignition of the vehicle is on, and determine that the utility power network 208 is not permitted to receive power from the utility power 220 when the utility power 220 is not connected to the utility power network 208 or the ignition of the vehicle is off.

If the utility power network 208 is connected to and permitted to receive power from the utility power 220, the method 400 proceeds to 410. If the utility power network 208 is not connected to the utility power 220 or the utility power network 208 is not permitted to receive power from the utility power 220, the method 400 proceeds to 415.

At 410, the vehicle electrical system 200 is operated with utility power. In particular, the AC-DC converter 225 converts the utility power 220 into DC power that is provided to the DC regulated bus 202. Also, the controller 260 is configured to control the vehicle isolator 215 so as to prevent power from the vehicle power network 204 to be supplied to DC regulated bus 202. The controller 260 is also configured to control the auxiliary power on/off switches 235 so as to prevent the auxiliary battery system 230 from supplying power to the DC regulated bus 202. Accordingly, the vehicle electrical system 200 can provide power to the transport climate control load network 212. In some embodiments, the controller 260 can also determine whether one or more of the auxiliary batteries of the auxiliary battery system 230 require charging. If charging is required, the controller 260 can be configured to operate the bi-directional voltage converter 240 in the charge mode so as to charge the one or more auxiliary batteries of the auxiliary battery system 230. If charging is not required, the controller 260 can be configured to operate the bi-directional voltage converter 240 in the null mode. A method for charging the auxiliary battery system 230 is discussed below with respect to FIG. 5. The method 400 then proceeds back to 405.

At 415, the controller 260 monitors a vehicle voltage or current provided by the vehicle power network 204 to the DC regulated bus 202. In some embodiments, a voltage sensor (not shown) is disposed in the vehicle power network 204 to measure the vehicle voltage. The voltage sensor then sends the vehicle voltage measurement to the controller 260. In some embodiments, a current sensor (not shown) can be disposed in the vehicle power network 204 to measure current coming into and out of the vehicle battery 210. In these embodiments, the current measurements can be sent to the controller 260 in lieu of the vehicle voltage measurement. The method 400 then proceeds to 420.

At 420, the controller 260 determines whether the vehicle power network 204 has excess power capacity available based on the vehicle voltage (or optionally the vehicle current) provided by the vehicle power network 204 to the DC regulated bus 202. The vehicle electrical system 200 can have excess power capacity available when, for example, the vehicle is highway cruising with limited stops or idling. Accordingly, the vehicle alternator 205 is supplying sufficient power to power the transport climate control network 212 by itself and can also supply power to the bi-directional voltage converter 240 to charge one or more auxiliary batteries of the auxiliary battery system 230. In some embodiments, when the vehicle power network 204 has excess power capacity available, the vehicle alternator 205 can supply power to the DC regulated bus 202 without assistance of the vehicle battery 210. In some embodiments, the controller 260 can determine that the vehicle power network 204 has excess power capacity available when the vehicle voltage is greater than an excess power capacity threshold. For example, when the DC regulated bus 202 is a 12 volt regulated bus, the controller 260 can determine that the vehicle power network 204 has excess power capacity available when the vehicle voltage provided by the vehicle power network 204 is greater than the excess power capacity threshold that is, for example, about 13.5 volts.

If the controller 260 determines that the vehicle power network 204 has excess power capacity available, the method 400 proceeds to 425. If the controller 260 determines that the vehicle power network 204 does not have excess power capacity available, the method 400 proceeds to 430.

At 425, the vehicle electrical system 200 operates with excess power capacity. In particular, the controller 260 is configured to control the vehicle isolator 215 so as to allow power from the vehicle power network 204 to be supplied to DC regulated bus 202. In some embodiments, the power from the vehicle power network 204 is from the vehicle alternator 205 without depleting charge of the vehicle battery 210. The controller 260 is also configured to control the auxiliary power on/off switches 235 so as to prevent the auxiliary battery system 230 from supplying power to the DC regulated bus 202. Accordingly, the vehicle electrical system 200 can provide power to the transport climate control load network 212 to operate the transport climate control system as desired.

In some embodiments, the controller 260 can also determine whether one or more of the auxiliary batteries of the auxiliary battery system 230 require charging. If charging is required, the controller 260 can be configured to operate the bi-directional voltage converter 240 in the charge mode so as to charge the one or more auxiliary batteries of the auxiliary battery system 230. If charging is not required, the controller 260 can be configured to operate the bi-voltage directional converter 240 in the null mode. Thus, the DC regulated bus 202 supplies required power to the transport climate control network 212 to operate the transport climate control system as desired and can supply any excess power available to the bi-directional voltage converter 240 to charge the auxiliary battery system 206. The method 400 then proceeds back to 405.

At 430, the controller 260 determines whether the vehicle power network 204 has sufficient power capacity available based on the vehicle voltage provided by the vehicle power network 204 to the DC regulated bus 202. The vehicle electrical system 200 can have sufficient power capacity available when, for example, the vehicle is city driving with stops and idling that can reduce the amount of power available by the vehicle alternator 205. Accordingly, the vehicle alternator 205, with potentially the assistance of the vehicle battery 210, can supply sufficient power to power the transport climate control network 212 but potentially not enough to also supply power to the bi-directional voltage converter 240 to charge one or more auxiliary batteries of the auxiliary battery system 230. In some embodiments, when the vehicle power network 204 has sufficient power capacity available, the vehicle alternator 205 supplies power to the DC regulated bus 202 with potentially the assistance of the vehicle battery 210, thereby depleting charge of the vehicle battery 210. In some embodiments, the controller 260 can determine that the vehicle power network 204 has sufficient power capacity available when the vehicle voltage is within a sufficient power capacity threshold range. For example, when the DC regulated bus 202 is a 12 volt regulated bus, the controller 260 can determine that the vehicle power network 204 has sufficient power capacity available when the vehicle voltage provided by the vehicle power network 204 is within the sufficient power capacity threshold range that is, for example, between about 13 volts and 13.5 volts.

If the controller 260 determines that the vehicle power network 204 has sufficient power capacity available, the method 400 proceeds to 435. If the controller 260 determines that the vehicle power network 204 does not have sufficient power capacity available, the method 400 proceeds to 480.

At 435, the vehicle electrical system 200 operates with sufficient power capacity. In particular, the controller 260 is configured to control the vehicle isolator 215 so as to allow power from the vehicle power network 204 to be supplied to the DC regulated bus 202. In some embodiments, the power from the vehicle power network 204 is from the vehicle alternator 205 and the vehicle battery 210, thereby depleting charge of the vehicle battery 210. The controller 260 is also configured to control the auxiliary power on/off switches 235 so as to prevent the auxiliary battery system 230 from supplying power to the DC regulated bus 202. Accordingly, the vehicle electrical system 200 can provide power to the transport climate control load network 212 as desired by the transport climate control system. In order to prevent significant discharge of the vehicle battery 210, the controller 260 can be configured to operate the bi-directional voltage converter 240 in the null mode and prevent charging of the auxiliary battery system 230. The method 400 then proceeds to 440.

At 440, the controller 260 monitors the power available capacity from the vehicle power network 204. This can occur when, for example, the vehicle is stopped or idling for a period of time and the load on the vehicle power network 204 is greater than can be provided by the vehicle power network 204. In some embodiments, the controller 260 can monitor the power available capacity from the vehicle power network 204 by monitoring the vehicle voltage provided by the vehicle power network 204 to the DC regulated bus 202 and/or by monitoring the vehicle current passing from the vehicle power network 204 to the DC regulated bus 202. In some embodiments, the controller 260 can monitor the power available capacity from the vehicle power network 204 by starting a timer. The timer can be set to a predetermined time period based on, for example, testing data of the vehicle electrical system 200. Also, in some embodiments, the controller 260 can monitor the power available capacity from the vehicle power network 204 by both monitoring the vehicle voltage (and/or vehicle current) and by starting the timer. In some embodiments, the timer can be set based on user requirements and in order to provide hysteresis and prevent mode cycling to the method 400. For example, in some embodiments, the timer can be set to a number of minutes (e.g., a number between 1 to 5 minutes). Significant discharge of the vehicle battery 210 can be a predetermined charge value of the vehicle battery 210 that is based on, for example, cargo customer requirements, vehicle requirements, and/or governmental regulations. For example, significant discharge of the vehicle battery 210 may be a charge value set to ensure that the vehicle battery can start a prime mover of the vehicle when the vehicle is not running. The method 400 then proceeds to 445.

At 445, the controller 260 determines whether the power available capacity has exceeded a capacity threshold. The capacity threshold can be a value that correlates with the battery power available capacity of the vehicle power network 204 and can be used to prevent, for example, significant discharge of the vehicle battery 210. In some embodiments, the capacity threshold can be a vehicle voltage value and/or a vehicle current value. In some embodiments, the capacity threshold can be a timer value. Also, in some embodiments, the controller 260 can use two capacity thresholds with the first capacity threshold being a vehicle voltage or current value and the second capacity threshold being a timer value.

If the controller 260 determines that the power available capacity monitored at 440 exceeds the capacity threshold, the method 400 proceeds back to 435. In embodiments where there are two capacity thresholds (e.g., the first capacity threshold being a vehicle voltage value and the second capacity threshold being a timer value) the controller 260 can determine that the power available capacity monitored at 440 exceeds the capacity threshold, when both the first capacity threshold and the second capacity threshold are exceeded. That is, the vehicle voltage value is greater than a vehicle voltage value threshold and the timer value has not been reached.

If the controller 260 determines that the power available capacity monitored at 440 does not exceed the capacity threshold, the method 400 proceeds to 455. In embodiments where there are two capacity thresholds (e.g., the first capacity threshold being a vehicle voltage or current value and the second capacity threshold being a timer value) the controller 260 can determine that the power available capacity monitored at 440 does not exceed the capacity threshold, when either the first capacity threshold or the second capacity threshold is exceeded. That is, the vehicle voltage value is less than or equal to a vehicle voltage threshold value or the timer value has been reached.

At 480, the controller 260 determines whether the auxiliary battery system 230 is sufficiently charged. In some embodiments, the controller 260 can determine the charge state of the auxiliary battery system 230 from the bi-directional voltage converter 240. In some embodiments, the auxiliary battery system 230 can be sufficiently charged if the charge state is above a charge state threshold (e.g., 20%). If the charge state of the auxiliary battery system 230 is above the charge state threshold (i.e., the auxiliary battery system 230 is sufficiently charged), the method 400 proceeds to 450. If the charge state of the auxiliary battery system 230 is below the charge state threshold (i.e., the auxiliary battery system 230 is not sufficiently charged), the method 400 proceeds to 470.

Also, in some embodiments, if the charge state is above the charge state threshold (i.e., the auxiliary battery system 230 is sufficiently charged) but lower than a second charge state threshold (e.g., 50%), the controller 260 can also send an alert, for example, to the user (e.g., vehicle driver), the cargo customer, etc. that there may be an energy scarcity of the vehicle electrical system 200. The alert can be sent via a SMS message, an email, can be displayed to the vehicle driver via the remote controller 280, etc. In some embodiments, the alert can instruct the driver to start the vehicle and run at a fast idle (e.g., raise an idle speed of a prime mover of the vehicle without raising a speed at which the vehicle is moving) or downshift a vehicle prime mover to operate at a higher prime mover RPM so as to prevent a failure of the transport climate control system and to prevent shedding or derating of loads of the transport climate control load network 212. In some embodiments, the controller 260 can instruct the vehicle to start an automatic restart module to start the vehicle and run at a fast idle to prevent failure of the transport climate control system and to prevent shedding or derating of loads of the transport climate control load network 212. In some embodiments, the controller 260 can instruct the vehicle to disable an auto start/stop system of the vehicle prime mover. In some embodiments, the alert can be sent a time period (e.g., 1 to 5 minutes) before any action is taken or required.

At 450, the controller 260 determines whether the vehicle power network 204 requires holdover assistance based on the vehicle voltage provided by the vehicle power network 204 to the DC regulated bus 202. The vehicle power network 204 can require holdover assistance when, for example, the vehicle alternator 205, with potentially the assistance of the vehicle battery 210, is not supplying sufficient power to power the transport climate control network 212. In some embodiments, when the vehicle power network 204 requires holdover assistance, the vehicle alternator 205 supplies power to the DC regulated bus 202 with potentially the assistance of the vehicle battery 210, thereby depleting charge of the vehicle battery 210. In some embodiments, the controller 260 can determine whether the vehicle power network requires holdover assistance when the vehicle voltage is within a holdover assistance threshold range. For example, when the DC regulated bus 202 is a 12 volt regulated bus, the controller 260 can determine that the vehicle power network 204 requires holdover assistance when the vehicle voltage provided by the vehicle power network 204 is within the holdover assistance threshold range that is, for example, between about 12 volts and 13 volts.

If the controller 260 determines that the vehicle power network 204 requires holdover assistance, the method 400 proceeds to 455. If the controller 260 determines that the vehicle power network 204 does not require holdover assistance, the method 400 proceeds to 460.

At 455, the vehicle electrical system 200 operates with holdover assistance. In particular, the controller 260 is configured to control the vehicle isolator 215 so as to allow power from the vehicle power network 204 to be supplied to the DC regulated bus 202. Also, the controller 260 is configured to control the auxiliary power on/off switches 235 so as to allow power from the auxiliary battery system 230 to be supplied to the to the DC regulated bus 202. The auxiliary battery system 230 can supplement the power provided by the vehicle power network 204 to ensure that the vehicle electrical system 200 can provide power to the transport climate control load network 212 as desired by the transport climate control system.

In some embodiments, the bi-directional voltage converter 240 can be set to a predetermined discharge voltage, for example, about 15V (or 14.2V that is closer to the nominal voltage the vehicle alternator 205 can provide). The bi-directional voltage converter 240 can run at a discharge mode, with a current limit of, for example, 40 A or 20 A or any suitable current required by the controller 260 to supplement the power from the vehicle power network 204. The method 400 then proceeds back to 405.

At 460, the controller 260 determines whether the vehicle electrical system 200 should be exclusively powered by the auxiliary battery system 230 based on the vehicle electrical system power capacity available from the vehicle power network 204 to the DC regulated bus 202. The vehicle power network 204 can exclusively use power from the auxiliary battery system 230 to power the DC regulated bus 202 when, for example, use of the vehicle power network 204 would significantly discharge the vehicle battery 210 (such as when the vehicle is not running). In some embodiments, when the vehicle electrical system 200 is exclusively powered by the auxiliary battery system 230, one or more of the auxiliary batteries of the auxiliary battery system 230 supplies power to the DC regulated bus 202 and the vehicle power network 204 is prevented from supplying power to the DC regulated bus 202. In some embodiments, the controller 260 can determine that the vehicle electrical system 200 should be exclusively powered by the auxiliary battery system 230 when the vehicle voltage is within an exclusive power threshold range. For example, when the DC regulated bus 202 is a 12 volt regulated bus, the controller 260 can determine that the vehicle electrical system 200 should be exclusively powered by the auxiliary battery system 230 when the vehicle voltage provided by the vehicle power network 204 is within the exclusive power threshold range that is, for example, between about 11.5 volts and 12 volts.

If the controller 260 determines that the vehicle electrical system 200 should be exclusively powered by the auxiliary battery system 230, the method 400 proceeds to 465. If the controller 260 determines that the vehicle electrical system 200 should not be exclusively powered by the auxiliary battery system 230, the method 400 proceeds to 470.

At 465, the vehicle electrical system 200 is powered exclusively by the auxiliary battery system 230. In particular, the controller 260 is configured to control a range of operation of the vehicle isolator 215 so as to prevent power from the vehicle power network 204 to be supplied to the DC regulated bus 202. Also, the controller 260 is configured to control the auxiliary power on/off switches 235 so as to allow power from the auxiliary battery system 230 to be supplied to the to the DC regulated bus 202. In some embodiments, the auxiliary battery system 230 can provide sufficient power to ensure that the vehicle electrical system 200 can provide power to the transport climate control load network 212 as desired by the transport climate control system. That is, in some embodiments, the auxiliary battery system 230 can bypass the bi-directional voltage converter 240 to supply the necessary current so the CDM 250 can operate to meet the transport climate control network demand. In other embodiments, the controller 260 can perform a load shedding process of the transport climate control load network 212 to reduce the amount of energy required by the DC regulated bus 202 and thereby the auxiliary power network 206 based on the amount of energy stored in the auxiliary battery system 230.

In some embodiments, the controller 260 can also send an alert, for example, to the user (e.g., vehicle driver), the cargo customer, etc. that there may be an energy scarcity of the vehicle electrical system 200. The alert can be sent via a SMS message, an email, can be displayed to the vehicle driver via the remote controller 280, etc. In some embodiments, the alert can instruct the driver to start the vehicle and run at a fast idle (e.g., raise an idle speed of a prime mover of the vehicle without raising a speed at which the vehicle is moving) or downshift a vehicle prime mover to operate at a higher prime mover RPM so as to prevent a failure of the transport climate control system and to prevent shedding or derating of loads of the transport climate control load network 212. In some embodiments, the controller 260 can instruct the vehicle to start an automatic restart module to start the vehicle and run at a fast idle to prevent failure of the transport climate control system and to prevent shedding or derating of loads of the transport climate control load network 212. In some embodiments, the controller 260 can instruct the vehicle to disable an auto start/stop system of the vehicle prime mover. In some embodiments, the alert can be sent a time period (e.g., 1 to 5 minutes) before any action is taken or required.

At 470, the controller 260 determines whether the vehicle electrical system 200 should shut off power to the transport climate control load network 212 based on the vehicle voltage provided by vehicle power network 204. That is, the controller 260 determines whether the DC regulated bus 202 should be prevented from receiving energy from the vehicle power network 204, the auxiliary power network 206 and, when applicable, the utility power network 208 and sending said energy to the components of the transport climate control load network 212. The vehicle electrical system 200 should shut off power to the transport climate control load network 212 when, for example, there is insufficient power available to power the transport climate control network 212 or could harm operation of the vehicle. In some embodiments, the controller 260 can determine that the vehicle electrical system 200 should shut off power to the transport climate control load network 212 when the vehicle voltage is less than a shut off threshold. For example, when the DC regulated bus 202 is a 12 volt regulated bus, the controller 260 can determine that the vehicle electrical system 200 should shut off power to the transport climate control load network 212 when the vehicle voltage provided by the vehicle power network 204 is less than the shut off threshold that is, for example, about 11.5 volts. If the controller 260 determines that the vehicle electrical system 200 should shut off power to the transport climate control load network 212, the method 400 proceeds to 475. If the controller 260 determines that the vehicle electrical system 200 does not have to shut off power to the transport climate control load network 212, the method 400 proceeds back to 405.

At 475, the controller 260 shuts off power from the vehicle electrical system 200 to the transport climate control load network 212. In some embodiments, the controller 260 can be configured to control the vehicle isolator 215 so as to prevent power from the vehicle power network 204 to be supplied to the DC regulated bus 202. Also, the controller 260 can be configured to control the auxiliary power on/off switches 235 so as to prevent power from the auxiliary battery system 230 to be supplied to the to the DC regulated bus 202. In some embodiments, the controller 260 can also be configured to control the AC-DC converter 225 so as to prevent power from the utility power 220.

In some embodiments, the controller 260 can also send an alert, for example, to the user (e.g., vehicle driver), the cargo customer, etc. The alert can be sent via a SMS message, an email, can be displayed to the vehicle driver via the remote controller 280, etc. In some embodiments, the alert can instruct the driver to start the vehicle and run at a fast idle (e.g., raise an idle speed of a prime mover of the vehicle without raising a speed at which the vehicle is moving) or downshift a vehicle prime mover to operate at a higher prime mover RPM so as to prevent a failure of the transport climate control system and to prevent shedding or derating of loads of the transport climate control load network 212. In some embodiments, the controller 260 can instruct the vehicle to start an automatic restart module to start the vehicle and run at a fast idle to prevent failure of the transport climate control system and to prevent shedding or derating of loads of the transport climate control load network 212. In some embodiments, the controller 260 can instruct the vehicle to disable an auto start/stop system of the vehicle prime mover. In some embodiments, the alert can be sent a time period (e.g., 1 to 5 minutes) before any action is taken or required.

The method 400 allows for energy management of the vehicle electrical system 200 as power from the vehicle power network 204 is decreasing. It will be appreciated that a similar methodology can be applied for energy management of the vehicle electrical system 200 as power from the vehicle power network 204 is increasing. When power from the vehicle power network 204 is increasing, the thresholds used for switching between power from the vehicle power network 204 and the auxiliary power network 206 can be the same or different as the thresholds provided in the method 400.

The embodiments described herein can address two different but related issues. The first issue is related to variable loads. The vehicle alternator 205 has nominal power capacity. In addition to the transport climate control system, the electrical system of the vehicle has other loads such as the lights of the vehicle, etc. Assuming that the power capacity of the vehicle alternator 205 is constant, as all the other loads (such as lights, fan, CD player, etc.) are switching on or off, the available power capacity for the transport climate control system is therefore not constant but variable. The second issue is related to the speed of the prime mover of the vehicle. Assuming the vehicle has a prime mover (e.g., a combustion engine such as a diesel engine, etc.), and the power capacity of the vehicle alternator 205 is driven or determined by the speed of the prime mover. If the vehicle is stopped at a traffic light and the prime mover is idling, the power capacity that the vehicle (for example from the vehicle alternator 205) can provide drops. If the vehicle is running at a cruising speed, then the vehicle alternator 205 can generate required current for powering the transport climate control system). Part of the current provided by the vehicle (for example, the vehicle alternator 205) can be used to power the vehicle's other loads (such as lights, fan, CD player, etc.). The rest of the current can be drawn to the transport climate control system.

Aspects:

It is to be appreciated that any of aspects 1-10 can be combined with any of aspects 11-20.

Aspect 1. A method for managing energy to a transport climate control system from a vehicle electrical system that includes a vehicle power network and an auxiliary power network connected to a transport climate control load network via a direct current (DC) regulated bus, the method comprising:

monitoring a vehicle voltage of the vehicle power network;

a controller determining whether the vehicle power network has sufficient power capacity available and whether the vehicle power network requires holdover assistance based on the vehicle voltage;

the DC regulated bus sending vehicle power energy generated by the vehicle power network to the transport climate control load network without assistance of the auxiliary power network when the controller determines that the vehicle power network has sufficient power capacity available; and

the DC regulated bus sending the vehicle power energy generated by the vehicle power network and auxiliary power energy stored by the auxiliary power network to the transport climate control load network when the controller determines that the vehicle power network requires holdover assistance.

Aspect 2. The method of aspect 1, further comprising:

the controller determining whether the vehicle power network has excess power capacity available based on the vehicle voltage;

the DC regulated bus sending vehicle power energy generated by the vehicle power network to the transport climate control load network and sending excess vehicle power energy generated by the vehicle power network not required by the transport climate control load network to a bi-directional voltage converter of the vehicle electrical system; and

the bi-directional voltage converter charging an auxiliary battery system of the auxiliary power network with the excess vehicle power energy generated by the vehicle power network not required by the transport climate control load network.

Aspect 3. The method of aspect 2, wherein the controller determining that the vehicle power network has excess power capacity available when the vehicle voltage is greater than an excess power capacity threshold.

Aspect 4. The method of any of aspects 1-3, further comprising:

the controller determining whether utility power energy provided by a utility power network is available to the vehicle electrical system; and

the DC regulated bus sending utility power energy provided by the utility power network to the transport climate control load network.

Aspect 5. The method of aspect 4, wherein the controller determining whether the utility power energy is available includes:

-   -   determining whether utility power is connected to a utility         power network of the vehicle electrical system, and     -   monitoring an ignition of the vehicle;     -   wherein the controller determines that the utility power energy         is available when the controller determines that the utility         power is connected to the utility power network and the ignition         of the vehicle is on.

Aspect 6. The method of any of aspects 1-5, further comprising:

the controller determining whether the vehicle electrical system should be exclusively powered by the auxiliary battery system based on the vehicle voltage; and

the DC regulated bus sending the auxiliary power energy stored by the auxiliary power network to the transport climate control network and preventing vehicle power energy generated by the vehicle power network to the transport climate control load network.

Aspect 7. The method of aspect 6, wherein the controller determining that the vehicle electrical system should be exclusively powered by the auxiliary battery system when the vehicle voltage is within an exclusive power threshold range.

Aspect 8. The method of any of aspects 1-7, further comprising:

upon the controller determining that the vehicle power network has sufficient power capacity available, the controller:

-   -   starting a timer,     -   monitoring a power available capacity of the vehicle power         network,     -   the controller determining that the vehicle power network         requires holdover assistance when at least one of the timer         ending and the power available capacity of the vehicle power         network exceeding a capacity threshold, and     -   the DC regulated bus sending vehicle power energy generated by         the vehicle power network and auxiliary power energy stored by         the auxiliary power network to the transport climate control         load network when the controller determines that the vehicle         power network requires holdover assistance.

Aspect 9. The method of any of aspects 1-8, further comprising:

the controller determining whether the vehicle electrical system should shut off power to the transport climate control load network based on the vehicle voltage; and

the controller preventing the DC regulated bus from receiving power from the vehicle power network and the auxiliary power network and sending power to the transport climate control load network when the controller determines that the vehicle electrical system should be shut off.

Aspect 10. The method of aspect 9, wherein the controller determining that the vehicle electrical system should shut off power to the transport climate control load network when the vehicle voltage is less than a shut off threshold.

Aspect 11. A vehicle electrical system for managing energy to a transport climate control system, the vehicle electrical system comprising:

a direct current (DC) regulated bus;

a vehicle power network configured to generate power from a vehicle and provide the generated power to the DC regulated bus;

an auxiliary power network that includes an auxiliary battery system connected to the DC regulated bus, wherein the auxiliary battery system is configured to store power and supply the stored power to the DC regulated bus;

a transport climate control load network receiving power from the DC regulated bus; and

a controller configured to monitor a vehicle voltage of the vehicle power network, and determine whether the vehicle power network has sufficient power capacity available and whether the vehicle power network requires holdover assistance based on the vehicle voltage,

wherein the DC regulated bus is configured to send vehicle power energy generated by the vehicle power network to the transport climate control load network without assistance of the auxiliary power network when the controller determines that the vehicle power network has sufficient power capacity available, and

wherein the DC regulated bus is configured to send vehicle power energy generated by the vehicle power network and auxiliary power energy stored by the auxiliary power network to the transport climate control load network when the controller determines that the vehicle power network requires holdover assistance.

Aspect 12. The vehicle electrical system of aspect 11, wherein the vehicle power network includes a vehicle alternator and a vehicle battery connected to the DC regulated bus.

Aspect 13. The vehicle electrical system of aspect 12, wherein the vehicle power network includes a vehicle isolator disposed between the vehicle alternator and the vehicle battery at first end and the DC regulated bus at a second end, and

wherein the controller is configured to control the vehicle isolator to prevent the vehicle power network from supplying power generated by the vehicle power network to the transport climate control network when the controller determines that the vehicle electrical system should be exclusively powered by the auxiliary battery system.

Aspect 14. The vehicle electrical system of any of aspects 12 and 13, further comprising a utility power network connected to the DC regulated bus and configured to supply utility power to the vehicle electrical system, wherein the utility power network includes an alternating current (AC)-DC converter that can be coupled to a utility power source,

wherein the vehicle power network includes a vehicle isolator disposed between the vehicle alternator and the vehicle battery at first end and the DC regulated bus at a second end, and

wherein the controller is configured to control the vehicle isolator to prevent the vehicle power network from supplying power generated by the vehicle power network to the transport climate control network when the controller determines that utility power from a utility power network is available.

Aspect 15. The vehicle electrical system of any of aspects 11-14, further comprising a utility power network connected to the DC regulated bus and configured to supply utility power to the vehicle electrical system, wherein the utility power network includes an alternating current (AC)-DC converter that can be coupled to a utility power source.

Aspect 16. The vehicle electrical system of aspect 15, further comprising a bi-directional voltage converter that is part of a smart charge module, wherein the smart charge module is configured to charge the auxiliary battery system with power supplied by the utility power network when the controller determines that the AC-DC converter is coupled to the utility power source.

Aspect 17. The vehicle electrical system of any of aspects 11-16, further comprising a bi-directional voltage converter connected to the auxiliary battery system and the DC regulated bus, wherein the bi-directional voltage converter is configured to transfer power from one of the vehicle power network and the auxiliary power network to the transport climate control load network.

Aspect 18. The vehicle electrical system of aspect 17, wherein the bi-directional voltage converter is part of a smart charge module that is configured to charge the auxiliary battery system with power generated by the vehicle power network when the controller determines that the vehicle power network has excess power capacity available.

Aspect 19. The vehicle electrical system of any of aspects 11-18, wherein the transport climate control load network includes a compressor drive module that drives a compressor of the transport climate control system.

Aspect 20. The vehicle electrical system of any of aspects 11-19, wherein the auxiliary power network includes a plurality of auxiliary power on/off switches disposed between the auxiliary battery system and the DC regulated bus,

wherein the controller is configured to control the auxiliary power on/off switches to prevent the auxiliary power network from supplying power stored in the auxiliary battery system to the transport climate control network when the controller determines that the vehicle power network has sufficient power capacity available and is configured to control the auxiliary power on/off switches to allow the auxiliary power network to supply power stored in the auxiliary battery system to the transport climate control network when the controller determines that the vehicle power network requires holdover assistance.

The terminology used in this specification is intended to describe particular embodiments and is not intended to be limiting. The terms “a,” “an,” and “the” include the plural forms as well, unless clearly indicated otherwise. The terms “comprises” and/or “comprising,” when used in this specification, indicate the presence of the stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and/or components.

With regard to the preceding description, it is to be understood that changes may be made in detail, especially in matters of the construction materials employed and the shape, size, and arrangement of parts, without departing from the scope of the present disclosure. The word “embodiment” as used within this specification may, but does not necessarily, refer to the same embodiment. This specification and the embodiments described are examples only. Other and further embodiments may be devised without departing from the basic scope thereof, with the true scope and spirit of the disclosure being indicated by the claims that follow. 

What is claimed is:
 1. A method for managing energy to a transport climate control system from a vehicle electrical system that includes a vehicle power network and an auxiliary power network connected to a transport climate control load network via a direct current (DC) regulated bus, the method comprising: monitoring a vehicle voltage of the vehicle power network; a controller determining whether the vehicle power network has sufficient power capacity available and whether the vehicle power network requires holdover assistance based on the vehicle voltage; the DC regulated bus sending vehicle power energy generated by the vehicle power network to the transport climate control load network without assistance of the auxiliary power network when the controller determines that the vehicle power network has sufficient power capacity available; and the DC regulated bus sending the vehicle power energy generated by the vehicle power network and auxiliary power energy stored by the auxiliary power network to the transport climate control load network when the controller determines that the vehicle power network requires holdover assistance.
 2. The method of claim 1, further comprising: the controller determining whether the vehicle power network has excess power capacity available based on the vehicle voltage; the DC regulated bus sending vehicle power energy generated by the vehicle power network to the transport climate control load network and sending excess vehicle power energy generated by the vehicle power network not required by the transport climate control load network to a bi-directional voltage converter of the vehicle electrical system; and the bi-directional voltage converter charging an auxiliary battery system of the auxiliary power network with the excess vehicle power energy generated by the vehicle power network not required by the transport climate control load network.
 3. The method of claim 2, wherein the controller determining that the vehicle power network has excess power capacity available when the vehicle voltage is greater than an excess power capacity threshold.
 4. The method of claim 1, further comprising: the controller determining whether utility power energy provided by a utility power network is available to the vehicle electrical system; and the DC regulated bus sending utility power energy provided by the utility power network to the transport climate control load network.
 5. The method of claim 4, wherein the controller determining whether the utility power energy is available includes: determining whether utility power is connected to a utility power network of the vehicle electrical system, and monitoring an ignition of the vehicle; wherein the controller determines that the utility power energy is available when the controller determines that the utility power is connected to the utility power network and the ignition of the vehicle is on.
 6. The method of claim 1, further comprising: the controller determining whether the vehicle electrical system should be exclusively powered by the auxiliary battery system based on the vehicle voltage; and the DC regulated bus sending the auxiliary power energy stored by the auxiliary power network to the transport climate control network and preventing vehicle power energy generated by the vehicle power network to the transport climate control load network.
 7. The method of claim 6, wherein the controller determining that the vehicle electrical system should be exclusively powered by the auxiliary battery system when the vehicle voltage is within an exclusive power threshold range.
 8. The method of claim 1, further comprising: upon the controller determining that the vehicle power network has sufficient power capacity available, the controller: starting a timer, monitoring a battery discharge of a vehicle battery of the vehicle power network, the controller determining that the vehicle power network requires holdover assistance when at least one of the timer ending and the power available capacity of the vehicle power network exceeding a capacity threshold, and the DC regulated bus sending vehicle power energy generated by the vehicle power network and auxiliary power energy stored by the auxiliary power network to the transport climate control load network when the controller determines that the vehicle power network requires holdover assistance.
 9. The method of claim 1, further comprising: the controller determining whether the vehicle electrical system should shut off power to the transport climate control load network based on the vehicle voltage; and the controller preventing the DC regulated bus from receiving power from the vehicle power network and the auxiliary power network and sending power to the transport climate control load network when the controller determines that the vehicle electrical system should be shut off.
 10. The method of claim 9, wherein the controller determining that the vehicle electrical system should shut off power to the transport climate control load network when the vehicle voltage is less than a shut off threshold.
 11. A vehicle electrical system for managing energy to a transport climate control system, the vehicle electrical system comprising: a direct current (DC) regulated bus; a vehicle power network configured to generate power from a vehicle and provide the generated power to the DC regulated bus; an auxiliary power network that includes an auxiliary battery system connected to the DC regulated bus, wherein the auxiliary battery system is configured to store power and supply the stored power to the DC regulated bus; a transport climate control load network receiving power from the DC regulated bus; and a controller configured to monitor a vehicle voltage of the vehicle power network, and determine whether the vehicle power network has sufficient power capacity available and whether the vehicle power network requires holdover assistance based on the vehicle voltage, wherein the DC regulated bus is configured to send vehicle power energy generated by the vehicle power network to the transport climate control load network without assistance of the auxiliary power network when the controller determines that the vehicle power network has sufficient power capacity available, and wherein the DC regulated bus is configured to send vehicle power energy generated by the vehicle power network and auxiliary power energy stored by the auxiliary power network to the transport climate control load network when the controller determines that the vehicle power network requires holdover assistance.
 12. The vehicle electrical system of claim 11, wherein the vehicle power network includes a vehicle alternator and a vehicle battery connected to the DC regulated bus.
 13. The vehicle electrical system of claim 12, wherein the vehicle power network includes a vehicle isolator disposed between the vehicle alternator and the vehicle battery at first end and the DC regulated bus at a second end, and wherein the controller is configured to control the vehicle isolator to prevent the vehicle power network from supplying power generated by the vehicle power network to the transport climate control network when the controller determines that the vehicle electrical system should be exclusively powered by the auxiliary battery system.
 14. The vehicle electrical system of claim 12, further comprising a utility power network connected to the DC regulated bus and configured to supply utility power to the vehicle electrical system, wherein the utility power network includes an alternating current (AC)-DC converter that can be coupled to a utility power source, wherein the vehicle power network includes a vehicle isolator disposed between the vehicle alternator and the vehicle battery at first end and the DC regulated bus at a second end, and wherein the controller is configured to control the vehicle isolator to prevent the vehicle power network from supplying power generated by the vehicle power network to the transport climate control network when the controller determines that utility power from a utility power network is available.
 15. The vehicle electrical system of claim 11, further comprising a utility power network connected to the DC regulated bus and configured to supply utility power to the vehicle electrical system, wherein the utility power network includes an alternating current (AC)-DC converter that can be coupled to a utility power source.
 16. The vehicle electrical system of claim 15, further comprising a bi-directional voltage converter that is part of a smart charge module, wherein the smart charge module is configured to charge the auxiliary battery system with power supplied by the utility power network when the controller determines that the AC-DC converter is coupled to the utility power source.
 17. The vehicle electrical system of claim 11, further comprising a b-directional voltage converter connected to the auxiliary battery system and the DC regulated bus, wherein the bi-directional voltage converter is configured to transfer power from one of the vehicle power network and the auxiliary power network to the transport climate control load network.
 18. The vehicle electrical system of claim 17, wherein the bi-directional voltage converter is part of a smart charge module that is configured to charge the auxiliary battery system with power generated by the vehicle power network when the controller determines that the vehicle power network has excess power capacity available.
 19. The vehicle electrical system of claim 11, wherein the transport climate control load network includes a compressor drive module that drives a compressor of the transport climate control system.
 20. The vehicle electrical system of claim 11, wherein the auxiliary power network includes a plurality of auxiliary power on/off switches disposed between the auxiliary battery system and the DC regulated bus, wherein the controller is configured to control the auxiliary power on/off switches to prevent the auxiliary power network from supplying power stored in the auxiliary battery system to the transport climate control network when the controller determines that the vehicle power network has sufficient power capacity available and is configured to control the auxiliary power on/off switches to allow the auxiliary power network to supply power stored in the auxiliary battery system to the transport climate control network when the controller determines that the vehicle power network requires holdover assistance. 